R for Windows 4.3.1 / 4.4.0 r85126 Pre-release

C-LEVEL FACILITIES:
The C-level API version of R's integrate(), Rdqags() in Applic.h, now returns the correct number of integrand evaluations neval, fixing PR#18515 reported and diagnosed by Stephen Wade.
The C prototypes for LAPACK calls dspgv and dtptrs in R_exts/Lapack.h had one too many and one too few character length arguments - but this has not caused any known issues. To get the corrected prototypes, include
#include <Rconfig.h> // for PR18534fixed
#ifdef PR18534fixed
# define usePR18534fix 1
#endif
#include <R_exts/Lapack.h>
in your C/C++ code.
INSTALLATION:
Many of the checks of esoteric Internet operations and those using unreliable external sites have been moved to a new target that is not run by default and primarily intended for the core developers. To run them use cd tests; make test-Internet-dev
BUG FIXES:
.S3methods(), typically called from methods(), again marks methods from package base as visible. Also, the visibility of non-base methods is again determined by the method's presence in search().
Tools::Rdiff() is now more robust against invalid strings, fixing installation tests on Windows without Rtools installed.
Fix (new) bug in hcl.colors(2, *), by Achim Zeileis.
Head(., <illegal>) and tail(..) now produce more useful "Error in...." error messages, fixing.
Package code syntax on Windows is checked in UTF-8 when UTF-8 is the native encoding.
Na.contiguous(x) now also returns the first run, when it is at the beginning and there is a later one of the same length; reported to R-devel, including a fix, by Georgi Boshnakov. Further, by default, it modifies only an existing attr(*,"tsp") but otherwise no longer sets one.
Chol(<not pos.def>, pivot = <T|F>) now gives a correct error or warning message (depending on pivot), thanks to Mikael Jagan's.

NEW FEATURES:
On platforms using configure option --with-internal-tzcode, additional values "internal" and (on macOS only) "macOS" are accepted for the environment variable TZDIR. (See ?TZDIR.)
On macOS, "macOS" is used by default if the system timezone database is a newer version than that in the R installation.
When install.packages(type = "source") fails to find a package in a repository it mentions package versions which are excluded by their R version requirement and links to hints on why a package might not be found.
The default value for options("timeout") can be set from enviromnent variable R_DEFAULT_INTERNET_TIMEOUT, still defaulting to 60 (seconds) if that is not set or invalid.
This may be needed when child R processes are doing downloads, for example during the installation of source packages which download jars or other forms of data.
LINK-TIME OPTIMIZATION on a UNIX-ALIKE:
There is now support for parallelized Link-Time Optimization (LTO) with GCC and for ‘thin’ LTO with clang via setting the LTO macro.
There is support for setting a different LTO flag for the Fortran compiler, including to empty when mixing clang and gfortran (as on macOS). See file ‘config.site’.
There is a new LTO_LD macro to set linker options for LTO compilation, for example to select an alternative linker or to parallelize thin LTO.
DEPRECATED AND DEFUNCT:
The LINPACK argument to chol.default(), chol2inv(), solve.default() and svd() has been defunct since R 3.1.0. Using it now gives a warning which will become an error in R 4.1.0.
BUG FIXES:
The code mitigating stack overflow with PCRE regexps on very long strings is enabled for PCRE2 < 10.30 also when JIT is enabled, since stack overflows have been seen in that case.
Fix to correctly show the group labels in dotchart() (which where lost in the ylab improvement for R 4.0.0).
addmargins(*, ..) now also works when fn() is a local function, thanks to bug report and patch PR#17124 from Alex Bertram.
rank(x) and hence sort(x) now work when x is an object (as per is.object(x)) of type "raw" and provides a valid `[` method, e.g., for gmp::as.bigz(.) numbers.
chisq.test(*, simulate.p.value=TRUE) and r2dtable() now work correctly for large table entries (in the millions). Reported by Sebastian Meyer and investigated by more helpers in PR#16184.
Low-level socket read/write operations have been fixed to correctly signal communication errors. Previously, such errors could lead to a segfault due to invalid memory access. Reported and debugged by Dmitriy Selivanov in PR#17850.
quantile(x, pr) works more consistently for pr values slightly outside [0,1], thanks to Suharto Anggono's PR#17891.
Further, quantile(x, prN, names=FALSE) now works even when prN contains NAs, thanks to Anggono's PR#17892. Ditto for ordered factors or Date objects when type = 1 or 3, thanks to PR#17899.
Libcurl-based internet access, including curlGetHeaders(), was not respecting the "timeout" option. If this causes unanticipated timeouts, consider increasing the default by setting R_DEFAULT_INTERNET_TIMEOUT.
as.Date(<char>) now also works with an initial "", thanks to Michael Chirico's PR#17909.
isS3stdGeneric(f) now detects an S3 generic also when it it is trace()d, thanks to Gabe Becker's PR#17917.
R_allocLD() has been fixed to return memory aligned for long double type PR#16534.
fisher.test() no longer segfaults when called again after its internal stack has been exceeded PR#17904.
Accessing a long vector represented by a compact integer sequence no longer segfaults (reported and debugged by Hugh Parsonage).
duplicated() now works also for strings with multiple encodings inside a single vector PR#17809.
phyper(11, 15, 0, 12, log.p=TRUE) no longer gives NaN; reported as PR#17271 by Alexey Stukalov.
Fix incorrect calculation in logLik.nls() PR#16100, patch from Sebastian Meyer.
A very old bug could cause a segfault in model.matrix() when terms involved logical variables. Part of PR#17879.
model.frame.default() allowed data = 1, leading to involuntary variable capture (rest of PR#17879).
tar() no longer skips non-directory files, thanks to a patch by Sebastian Meyer, fixing the remaining part of PR#16716.

BUG FIXES:
raw(0) & raw(0) and raw(0) | raw(0) again return raw(0) (rather than logical(0)).
intToUtf8() converts integers corresponding to surrogate code points to NA rather than invalid UTF-8, as well as values larger than the current Unicode maximum of 0x10FFFF. (This aligns with the current RFC3629.)
Fix calling of methods on S4 generics that dispatch on ... when the call contains ....
Following Unicode 'Corrigendum 9', the UTF-8 representations of U+FFFE and U+FFFF are now regarded as valid by utf8ToInt().
range(c(TRUE, NA), finite = TRUE) and similar no longer return NA.
The self starting function attr(SSlogis, "initial") now also works when the y values have exact minimum zero and is slightly changed in general, behaving symmetrically in the y range.
The printing of named raw vectors is now formatted nicely as for other such atomic vectors, thanks to Lukas Stadler.

INSTALLATION on a UNIX-ALIKE:
The deprecated support for PCRE versions older than 8.20 has been removed.
BUG FIXES:
getParseData() gave incorrect column information when code contained multi-byte characters. (PR#17254)
Asking for help using expressions like ?stats::cor() did notwork. (PR#17250)
readRDS(url(....)) now works.
R CMD Sweave again returns status = 0 on successful completion.
Vignettes listed in .Rbuildignore were not being ignored properly. (PR#17246)
file.mtime() no longer returns NA on Windows when the file or directory is being used by another process. This affected installed.packages(), which is now protected against this.
R CMD INSTALL Windows .zip file obeys --lock and --pkglock flags.
(Windows only) The choose.files() function could return incorrect results when called with multi = FALSE. (PR#17270)
aggregate(<data.frame>, drop = FALSE) now also works in case of near-equal numbers in by. (PR#16918)
fourfoldplot() could encounter integer overflow when calculating the odds ratio. (PR#17286)
parse() no longer gives spurious warnings when extracting srcrefs from a file not encoded in the current locale.
This was seen from R CMD check with inst/doc/*.R files, and check has some additional protection for such files.
print.noquote(x) now always returns its argument x (invisibly).
Non-UTF-8 multibyte character sets were not handled properly in source references. (PR#16732)

SIGNIFICANT USER-VISIBLE CHANGES

nchar(x, *)'s argument keepNA governing how the result for NAs in x is determined, gets a new default keepNA = NA which returns NA where x is NA, except for type = "width" which still returns 2, the formatting / printing width of NA.

All builds have support for https: URLs in the default methods for download.file(), url() and code making use of them.

Unfortunately that cannot guarantee that any particular https: URL can be accessed. For example, server and client have to successfully negotiate a cryptographic protocol (TLS/SSL, ...) and the server's identity has to be verifiable via the available certificates. Different access methods may allow different protocols or use private certificate bundles: we encountered a https: CRAN mirror which could be accessed by one browser but not by another nor by download.file() on the same Linux machine.

NEW FEATURES

The print method for methods() gains a byclass argument.

New functions validEnc() and validUTF8() to give access to the validity checks for inputs used by grep() and friends.

Experimental new functionality for S3 method checking, notably isS3method().

Also, the names of the R ‘language elements’ are exported as character vector tools::langElts.

str(x) now displays "Time-Series" also for matrix (multivariate) time-series, i.e. when is.ts(x) is true.

(Windows only) The GUI menu item to install local packages now accepts ‘*.tar.gz’ files as well as ‘*.zip’ files (but defaults to the latter).

New programmeR's utility function chkDots().

D() now signals an error when given invalid input, rather than silently returning NA. (Request of John Nash.)

formula objects are slightly more “first class”: e.g., formula() or new("formula", y ~ x) are now valid. Similarly, for "table", "ordered" and "summary.table". Packages defining S4 classes with the above S3/S4 classes as slots should be reinstalled.

New function strrep() for repeating the elements of a character vector.

rapply() preserves attributes on the list when how = "replace".

New S3 generic function sigma() with methods for extracting the estimated standard deviation aka “residual standard deviation” from a fitted model.

news() now displays R and package news files within the HTML help system if it is available. If no news file is found, a visible NULL is returned to the console.

as.raster(x) now also accepts raw arrays x assuming values in 0:255.

Subscripting of matrix/array objects of type "expression" is now supported.

type.convert("i") now returns a factor instead of a complex value with zero real part and missing imaginary part.

Graphics devices cairo_pdf() and cairo_ps() now allow non-default values of the cairographics ‘fallback resolution’ to be set.

This now defaults to 300 on all platforms: that is the default documented by cairographics, but apparently was not used by all system installations.

file() gains an explicit method argument rather than implicitly using getOption("url.method", "default").

Thanks to a patch from Tomas Kalibera, x[x != 0] is now typically faster than x[which(x != 0)] (in the case where x has no NAs, the two are equivalent).

read.table() now always uses the names for a named colClasses argument (previously names were only used when colClasses was too short). (In part, wish of PR#16478.)

(Windows only) download.file() with default method = "auto" and a ftps:// URL chooses "libcurl" if that is available.

The out-of-the box Bioconductor mirror has been changed to one using https://: use chooseBioCmirror() to choose a http:// mirror if required.

The data frame and formula methods for aggregate() gain a drop argument.

available.packages() gains a repos argument.

The undocumented switching of methods for url() on https: and ftps: URLs is confined to method = "default" (and documented).

smoothScatter() gains a ret.selection argument.

qr() no longer has a ... argument to pass additional arguments to methods.

[ has a method for class "table".

It is now possible (again) to replayPlot() a display list snapshot that was created by recordPlot() in a different R session.

It is still not a good idea to use snapshots as a persistent storage format for R plots, but it is now not completely silly to use a snapshot as a format for transferring an R plot between two R sessions.

The underlying changes mean that packages providing graphics devices (e.g., Cairo, RSvgDevice, cairoDevice, tikzDevice) will need to be reinstalled.

Code for restoring snapshots was contributed by Jeroen Ooms and JJ Allaire.

Some testing code is available at https://github.com/pmur002/R-display-list.

tools::undoc(dir = D) and codoc(dir = D) now also work when D is a directory whose normalizePath()ed version does not end in the package name, e.g. from a symlink.

abbreviate() has more support for multi-byte character sets – it no longer removes bytes within characters and knows about Latin vowels with accents. It is still only really suitable for (most) European languages, and still warns on non-ASCII input.

abbreviate(use.classes = FALSE) is now implemented, and that is more suitable for non-European languages.

match(x, table) is faster (sometimes by an order of magnitude) when x is of length one and incomparables is unchanged, thanks to Peter Haverty (PR#16491).

More consistent, partly not back-compatible behavior of NA and NaN coercion to complex numbers, operations less often resulting in complex NA (NA_complex_).

lengths() considers methods for length and [[ on x, so it should work automatically on any objects for which appropriate methods on those generics are defined.

The logic for selecting the default screen device on OS X has been simplified: it is now quartz() if that is available even if environment variable DISPLAY has been set by the user.

The choice can easily be overridden via environment variable R_INTERACTIVE_DEVICE.

On Unix-like platforms which support the getline C library function, system(*,intern = TRUE) no longer truncates (output) lines longer than 8192 characters, thanks to Karl Millar. (PR#16544)

rank() gains a ties.method = "last" option, for convenience (and symmetry).

regmatches(invert = NA) can now be used to extract both non-matched and matched substrings.

data.frame() gains argument fix.empty.names; as.data.frame.list() gets new cut.names, col.names and fix.empty.names.

plot(x ~ x, *) now warns that it is the same as plot(x ~ 1, *).

recordPlot() has new arguments load and attach to allow package names to be stored as part of a recorded plot. replayPlot() has new argument reloadPkgs to load/attach any package names that were stored as part of a recorded plot.

S4 dispatch works within calls to .Internal(). This means explicit S4 generics are no longer needed for unlist() and as.vector().

Only font family names starting with "Hershey" (and not "Her" as before) are given special treatment by the graphics engine.

S4 values are automatically coerced to vector (via as.vector) when subassigned into atomic vectors.

findInterval() gets a left.open option.

The version of LAPACK included in the sources has been updated to 3.6.0, including those ‘deprecated’ routines which were previously included. Ca 40 double-complex routines have been added at the request of a package maintainer.

As before, the details of what is included are in ‘src/modules/lapack/README’ and this now gives information on earlier additions.

tapply() has been made considerably more efficient without changing functionality, thanks to proposals from Peter Haverty and Suharto Anggono. (PR#16640)

match.arg(arg) (the one-argument case) is faster; so is sort.int(). (PR#16640)

The format method for object_size objects now also accepts “binary” units such as "KiB" and e.g., "Tb". (Partly from PR#16649.)

Profiling now records calls of the form foo::bar and some similar cases directly rather than as calls to <Anonymous>. Contributed by Winston Chang.

New string utilities startsWith(x, prefix) and endsWith(x, suffix). Also provide speedups for some grepl("^...",*) uses (related to proposals in PR#16490).

Reference class finalizers run at exit, as well as on garbage collection.

Avoid parallel dependency on stats for port choice and random number seeds. (PR#16668)

The radix sort algorithm and implementation from data.table (forder) replaces the previous radix (counting) sort and adds a new method for order(). Contributed by Matt Dowle and Arun Srinivasan, the new algorithm supports logical, integer (even with large values), real, and character vectors. It outperforms all other methods, but there are some caveats (see ?sort).

The order() function gains a method argument for choosing between "shell" and "radix".

New function grouping() returns a permutation that stably rearranges data so that identical values are adjacent. The return value includes extra partitioning information on the groups. The implementation came included with the new radix sort.

rhyper(nn, m, n, k) no longer returns NA when one of the three parameters exceeds the maximal integer.

switch() now warns when no alternatives are provided.

parallel::detectCores() now has default logical = TRUE on all platforms – as this was the default on Windows, this change only affects Sparc Solaris.

Option logical = FALSE is now supported on Linux and recent versions of OS X (for the latter, thanks to a suggestion of Kyaw Sint).

hist() for "Date" or "POSIXt" objects would sometimes give misleading labels on the breaks, as they were set to the day before the start of the period being displayed. The display format has been changed, and the shift of the start day has been made conditional on right = TRUE (the default). (PR#16679)

R now uses a new version of the logo (donated to the R Foundation by RStudio). It is defined in ‘.svg’ format, so will resize without unnecessary degradation when displayed on HTML pages—there is also a vector PDF version. Thanks to Dirk Eddelbuettel for producing the corresponding X11 icon.

New function .traceback() returns the stack trace which traceback() prints.

lengths() dispatches internally.

dotchart() gains a pt.cex argument to control the size of points separately from the size of plot labels. Thanks to Michael Friendly and Milan Bouchet-Valat for ideas and patches.

as.roman(ch) now correctly deals with more diverse character vectors ch; also arithmetic with the resulting roman numbers works in more cases. (PR#16779)

prcomp() gains a new option rank. allowing to directly aim for less than min(n,p) PC's. The summary() and its print() method have been amended, notably for this case.

gzcon() gains a new option text, which marks the connection as text-oriented (so e.g. pushBack() works). It is still always opened in binary mode.

The import() namespace directive now accepts an argument except which names symbols to exclude from the imports. The except expression should evaluate to a character vector (after substituting symbols for strings). See Writing R Extensions.

New convenience function Rcmd() in package tools for invoking R CMD tools from within R.

New functions makevars_user() and makevars_site() in package tools to determine the location of the user and site specific ‘Makevars’ files for customizing package compilation.

UTILITIES

R CMD check has a new option --ignore-vignettes for use with non-Sweave vignettes whose VignetteBuilder package is not available.

R CMD check now by default checks code usage (via codetools) with only the base package attached. Functions from default packages other than base which are used in the package code but not imported are reported as undefined globals, with a suggested addition to the NAMESPACE file.

R CMD check --as-cran now also checks DOIs in package ‘CITATION’ and Rd files.

R CMD Rdconv and R CMD Rd2pdf each have a new option --RdMacros=pkglist which allows Rd macros to be specified before processing.

DEPRECATED AND DEFUNCT

The previously included versions of zlib, bzip2, xz and PCRE have been removed, so suitable external (usually system) versions are required (see the ‘R Installation and Administration’ manual).

The unexported and undocumented Windows-only devices cairo_bmp(), cairo_png() and cairo_tiff() have been removed. (These devices should be used as e.g. bmp(type = "cairo").)

(Windows only) Function setInternet2() has no effect and will be removed in due course. The choice between methods "internal" and "wininet" is now made by the method arguments of url() and download.file() and their defaults can be set via options. The out-of-the-box default remains "wininet" (as it has been since R 3.2.2).

[<- with an S4 value into a list currently embeds the S4 object into its own list such that the end result is roughly equivalent to using [[<-. That behavior is deprecated. In the future, the S4 value will be coerced to a list with as.list().

Package tools' functions package.dependencies(), pkgDepends(), etc are deprecated now, mostly in favor of package_dependencies() which is both more flexible and efficient.

INSTALLATION and INCLUDED SOFTWARE

Support for very old versions of valgrind (e.g., 3.3.0) has been removed.

The included libtool script (generated by configure) has been updated to version 2.4.6 (from 2.2.6a).

libcurl version 7.28.0 or later with support for the https protocol is required for installation (except on Windows).

BSD networking is now required (except on Windows) and so capabilities("http/ftp") is always true.

configure uses pkg-config for PNG, TIFF and JPEG where this is available. This should work better with multiple installs and with those using static libraries.

The minimum supported version of OS X is 10.6 (‘Snow Leopard’): even that has been unsupported by Apple since 2012.

The configure default on OS X is --disable-R-framework: enable this if you intend to install under ‘/Library/Frameworks’ and use with R.app.

The minimum preferred version of PCRE has since R 3.0.0 been 8.32 (released in Nov 2012). Versions 8.10 to 8.31 are now deprecated (with warnings from configure), but will still be accepted until R 3.4.0.

configure looks for C functions __cospi, __sinpi and __tanpi and uses these if cospi etc are not found. (OS X is the main instance.)

(Windows) R is now built using gcc 4.9.3. This build will require recompilation of at least those packages that include C++ code, and possibly others. A build of R-devel using the older toolchain will be temporarily available for comparison purposes.

During the transition, the environment variable R_COMPILED_BY has been defined to indicate which toolchain was used to compile R (and hence, which should be used to compile code in packages). The COMPILED_BY variable described below will be a permanent replacement for this.

(Windows) A make and R CMD config variable named COMPILED_BY has been added. This indicates which toolchain was used to compile R (and hence, which should be used to compile code in packages).

PACKAGE INSTALLATION

The make macro AWK which used to be made available to files such as ‘src/Makefile’ is no longer set.

C-LEVEL FACILITIES

The API call logspace_sum introduced in R 3.2.0 is now remapped as an entry point to Rf_logspace_sum, and its first argument has gained a const qualifier. (PR#16470)

Code using it will need to be reinstalled.

Similarly, entry point log1pexp also defined in ‘Rmath.h’ is remapped there to Rf_log1pexp

R_GE_version has been increased to 11.

New API call R_orderVector1, a faster one-argument version of R_orderVector.

When R headers such as ‘R.h’ and ‘Rmath.h’ are called from C++ code in packages they include the C++ versions of system headers such as ‘<cmath>’ rather than the legacy headers such as ‘<math.h>’. (Headers ‘Rinternals.h’ and ‘Rinterface.h’ already did, and inclusion of system headers can still be circumvented by defining NO_C_HEADERS, including as from this version for those two headers.)

The manual has long said that R headers should not be included within an extern "C" block, and almost all the packages affected by this change were doing so.

Including header ‘S.h’ from C++ code would fail on some platforms, and so gives a compilation error on all.

The deprecated header ‘Rdefines.h’ is now compatible with defining R_NO_REMAP.

The connections API now includes a function R_GetConnection() which allows packages implementing connections to convert R connection objects to Rconnection handles used in the API. Code which previously used the low-level R-internal getConnection() entry point should switch to the official API.

BUG FIXES

C-level asChar(x) is fixed for when x is not a vector, and it returns "TRUE"/"FALSE" instead of "T"/"F" for logical vectors.

The first arguments of .colSums() etc (with an initial dot) are now named x rather than X (matching colSums()): thus error messages are corrected.

A coef() method for class "maov" has been added to allow vcov() to work with multivariate results. (PR#16380)

method = "libcurl" connections signal errors rather than retrieving HTTP error pages (where the ISP reports the error).

xpdrows.data.frame() was not checking for unique row names; in particular, this affected assignment to non-existing rows via numerical indexing. (PR#16570)

tail.matrix() did not work for zero rows matrices, and could produce row “labels” such as "[1e+05,]".

Data frames with a column named "stringsAsFactors" now format and print correctly. (PR#16580)

cor() is now guaranteed to return a value with absolute value less than or equal to 1. (PR#16638)

Array subsetting now keeps names(dim(.)).

Blocking socket connection selection recovers more gracefully on signal interrupts.

The data.frame method of rbind() construction row.names works better in borderline integer cases, but may change the names assigned. (PR#16666)

(X11 only) getGraphicsEvent() miscoded buttons and missed mouse motion events. (PR#16700)

methods(round) now also lists round.POSIXt.

tar() now works with the default files = NULL. (PR#16716)

Jumps to outer contexts, for example in error recovery, now make intermediate jumps to contexts where on.exit() actions are established instead of trying to run all on.exit() actions before jumping to the final target. This unwinds the stack gradually, releases resources held on the stack, and significantly reduces the chance of a segfault when running out of C stack space. Error handlers established using withCallingHandlers() and options("error") specifications are ignored when handling a C stack overflow error as attempting one of these would trigger a cascade of C stack overflow errors. (These changes resolve PR#16753.)

The spacing could be wrong when printing a complex array. (Report and patch by Lukas Stadler.)

pretty(d, n, min.n, *) for date-time objects d works again in border cases with large min.n, returns a labels attribute also for small-range dates and in such cases its returned length is closer to the desired n. (PR#16761) Additionally, it finally does cover the range of d, as it always claimed.

tsp(x) <- NULL did not handle correctly objects inheriting from both "ts" and "mts". (PR#16769)

install.packages() could give false errors when options("pkgType") was "binary". (Reported by Jose Claudio Faria.)

A bug fix in R 3.0.2 fixed problems with locator() in X11, but introduced problems in Windows. Now both should be fixed. (PR#15700)

download.file() with method = "wininet" incorrectly warned of download file length difference when reported length was unknown. (PR#16805)

diag(NULL, 1) crashed because of missed type checking. (PR#16853)

SIGNIFICANT USER-VISIBLE CHANGES:
It is now easier to use secure downloads from https:// URLs on builds which support them: no longer do non-default options need to be selected to do so. In particular, packages can be installed from repositories which offer https:// URLs, and those listed by setRepositories() now do so (for some of their mirrors)
Support for https:// URLs is available on Windows, and on other platforms if support for libcurl was compiled in and if that supports the https protocol (system installations can be expected to do). So https:// support can be expected except on rather old OSes (an example being OS X 'Snow Leopard', where a non-system version of libcurl can be used)
(Windows only) The default method for accessing URLs _via_ download.file() and url() has been changed to be "wininet" using Windows API calls. This changes the way proxies need to be set and security settings made: there have been some reports of sites being inaccessible under the new default method (but the previous methods remain available)
NEW FEATURES:
cmdscale() gets new option list. for increased flexibility when a list should be returned
configure now supports texinfo version 6.0, which (unlike the change from 4.x to 5.0) is a minor update. (Wish of PR#16456.)
(Windows only) setInternet2(TRUE) is now the default. The command-line option --internet2 and environment variable R_WIN_INTERNET2 are now ignored. Thus by default the "internal" method for download.file() and url() uses the "wininet" method: to revert to the previous default use setInternet2(FALSE). This means that https:// can be read by default by download.file() (they have been readable by file() and url() since R 3.2.0). There are implications for how proxies need to be set (see download.file): also, cacheOK = FALSE is not supported
chooseCRANmirror() and chooseBioCmirror() now offer HTTPS mirrors in preference to HTTP mirrors. This changes the interpretation of their ind arguments: see their help pages
capture.output() gets optional arguments type and split to pass to sink(), and hence can be used to capture messages
C-LEVEL FACILITIES:
Header Rconfig.h now defines HAVE_ALLOCA_H if the platform has the alloca.h header (it is needed to define alloca on Solaris and AIX, at least: see 'Writing R Extensions' for how to use it)
INSTALLATION and INCLUDED SOFTWARE:
The libtool script generated by configure has been modified to support FreeBSD >= 10 (PR#16410)
BUG FIXES:
The HTML help page links to demo code failed due to a change in R 3.2.0. (PR#16432)
If the na.action argument was used in model.frame(), the original data could be modified. (PR#16436)
getGraphicsEvent() could cause a crash if a graphics window was closed while it was in use. (PR#16438)
matrix(x, nr, nc, byrow = TRUE) failed if x was an object of type "expression"
strptime() could overflow the allocated storage on the C stack when the timezone had a non-standard format much longer than the standard formats. (Part of PR#16328.)
options(OutDec = s) now signals a warning (which will become an error in the future) when s is not a string with exactly one character, as that has been a documented requirement
prettyNum() gains a new option input.d.mark which together with other changes, e.g., the default for decimal.mark, fixes some format()ting variants with non-default getOption("OutDec") such as in PR#16411
download.packages() failed for type equal to either "both" or "binary".
The dendrogram method of labels() is much more efficient for large dendrograms, now using rapply(). (Comment #15 of PR#15215)
The "port" algorithm of nls() could give spurious errors
Reference classes that inherited from reference classes in another package could invalidate methods of the inherited class. Fixing this requires adding the ability for methods to be "external", with the object supplied explicitly as the first argument, named .self. See "Inter-Package Superclasses" in the documentation
readBin() could fail on the SPARC architecture due to alignment issues.
qt(*, df=Inf, ncp=.) now uses the natural qnorm() limit instead of returning NaN. (PR#16475)
Auto-printing of S3 and S4 values now searches for print() in the base namespace and show() in the methods namespace instead of searching the global environment
polym() gains a coefs = NULL argument and returns class "poly" just like poly() which gets a new simple=FALSE option. They now lead to correct predict()ions, e.g., on subsets of the original data
rhyper(nn, ) now works correctly. (PR#16489)
ttkimage() did not (and could not) work so was removed. Ditto for tkimage.cget() and tkimage.configure(). Added two Ttk widgets and missing subcommands for Tk's image command: ttkscale() ttkspinbox(), tkimage.delete(), tkimage.height(), tkimage.inuse(), tkimage.type(), tkimage.types(), tkimage.width(). (PR#15372, PR#16450)
getClass("foo") now also returns a class definition when it is found in the cache more than once